Phthalocyanine pigments



United States Patent Cfifice 3,004,986 Patented Oct. 17, 1961 3,004,986 PHTHALOCYANINE PIGMENTS Ben H. Kirby, Lock Haven, Pa., and Samuel E. Getty, Toms River, N.J., assignors, by mesne assignments, to Standard Ultramarine & Color Company, Huntington, W. Va., a corporation of West Virginia No Drawing. Filed Feb. 8, 1957, Ser. No. 638,921

r 17 Claims. (Cl. 260314.5)

This invention relates to the preparation of phthalocyanine pigments.

The usual methods for forming pigments of copper phthalocyanine and hexadecachloro copper phthalocyanine depend on acid pasting or acid milling of the crude base, followed by drowning in water. If the pigmented product is filtered and dried without any further after-treatment, the resulting powder is very hard and bronzy, and when used in paints, varnishes and lacquers or with plastics, the color value, shade and brilliance are reduced to a considerable extent.

To overcome this difiiculty, many proposals have been made employing, for example, the use of various surface active agents, after-treatments with rosin soaps, barium lakes, etc. to give products which dry down into soft and flulfy powders and, therefore, can be easily ground into the medium for which they'are used as coloring agents.

Although some of these prior processes have the advantage of increasing color strength, they have the disadvantage when used as a full strength toner that the agents employed for after-treatment are retained in the pigment.

Accordingly, it is an object of the present invention to devise an after-treatment agent for phthalocyanine pigments which can be readily removed from the pigment prior to use.

Another object is to prepare phthalocyanine pigments of increased strength.

An additional object is to prepare phthalocyanine pigments having improved dispersion properties.

A further object is to prepare copper phthalocyanine and chloro copper phthalocyanine pigments that can be used as full strength toners.

A still further object is to obtain plastic compositions containing phthalocyanine pigment toners of increased strength even without premixing of the plastic materials and toners.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by Way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

It has now been found that these objects can be attained by preparing a pigmented phthalocyanine presscake in conventional manner by acid pasting or acid milling, drowning and filtering and then employing the novel steps of slurrying into water containing a minor amount of an unsubstituted monohydric alcohol having at least three carbon atoms.

In the present specification and claims, all percentages and parts are by weight unless otherwise noted.

The preferred alcohols of the present invention are water insoluble straight and branched chain alkanols having to 12 carbon atoms and the most preferred alcohol is isooctyl alcohol.

Among the alcohols which can be used may be mentioned isopropyl alcohol, commercial mixed amyl alcohols, n-heptanol, lauryl alcohol, n-butyl alcohol, isobutyl alcohol, sec. butyl alcohol, t-butyl alcohol, n-hexyl alcohol, n-octyl alcohol, octanol-2 n-decyl alcohol and cyclohexanol.

As the phthalocyanines, there can be used copper phthalocyanine, chlorophthaloeyanines, such as octachloro copper phthalocyanine, dodecachloro copper phthalocyanine and hexadecaehloro copper phthalocyanine, aluminum phthalocyanine, hexadecachloro aluminum phthalocyanine, etc.

The preferred 'phthalocyanines are copper phthalocyanine and hexadecachloro copper phthalocyanine.

The initial acid pasting step is carried out in conventional manner using sulfuric acid of 90% to 100% concentration and in an amount of 3 to 20 parts per part of phthalocyanine. After acid pasting, until the pigment is dissolved or dispersed, e.g., by acid pasting for l to 8 hours, the phthalocyanine is drowned in conventional fashion with a large amount of water, e.g., suflicient water to give a sulfuric acid concentration of not over 15% and generally not over 10%. The precipitate is then filtered and the presscake employed as the starting material for the present invention. The presscake usually is about 1 part phthalocyanine and 2 parts liquid, al though this can vary from 1 to 3 parts of aqueous liquid per part of phthalocyanine.

The presscakeis then treated with a mixture of 4 to 20 parts of water and 0.01 to 0.25 part of the monohydn'c alcohol per part of phthalocyanine basis). The exact amount of water is not critical as the use of over 20 parts of water does not show any additional advantages. The pigmented phthalocyanine presscake is slurried into the water-monohydric alcohol mixture and stirred at 15- 100 C. for a short period of time, e.g., 1 to 3 hours.

The temperature of treatment is not critical. With slow speed agitation higher temperatures should be used, while with higher speed agitation, room temperature is sufiicient to give a satisfactory product.

The product obtained by this treatment is then filtered, dried in a conventional air drier and ground to give a soft powder. At the same time, the volatile after-treating agent is evaporated during the drying stage. The soft, easily ground fiufiy powder can be employed as a full strength toner in any application. a i

It has surprisingly been found that the phthalocyanine pigments prepared according to the present invention are especially adapted for use with. plastics, e.g., vinyl and vinylidene resins and rubbers such as polyethylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethyl acrylate copolymer, polystyrene, polymerized methyl methacrylate, polymerized methyl a-chloroacrylate, acrylonitn'le resins, and vinylidene chloride resins, natural rubber latex, rubbery butadienestyrene copolymer, etc. Without any premixing of the plastic materials and the present pigment toners, there is a 2550% increase in strength over conventional phthalocyanine pigments.- This is true even though the toner is reduced in tinting strength by means of titanium dioxide or other white pigments. Generally, .01 to 2 parts of our phthalocyanine pigments are used with 100 parts of plastic.

Example 1 Into a fiask equipped with an agitator and thermometer were placed 700 parts of water and parts of hex-adecachloro copperphthalocyanine presscake (equivalent to 60 parts of the phthalocyanine on a 100% pigment basis). The presscake was obtained by conventional :acid pasting with 3.5 parts of 95.2% sulfuric acid per part'of the phthalocyanine, drowning in 14 parts of water per part of phthalocyanine and then filtering. Agitation was begun and continueduntil most of the large particles were broken up and a uniform slurry obtained. Then there were added 1.5 parts of isooctyl alcohol. (The isooctyl alcohol was a mixture of isomeric octyl lines 35-71).

steam untiLaJempcrature of 60" C. Was reached and. the slurry-was held atthis' temperatureforl hours;;" The,

, 3 alcohols prepared by the oxo process and is described more fully in Davie Patent' Nor 2,732,291, column-4,- The whole mixture was heated with live product was filtered oil by suction :at the water purnpand theflask rinsed "with"; water. andrthe presscake dried at 100'C."in ahot airdrier.-

l The driedmaterial was bright green-in appearancejand; after conventional grinding through a micropulverizer,

the product was ready for use.

Clear, brilliant shades were obtained by using this material 'in'allfapplications. In plastic applications,- it :was especiallyoutstanding since it imparted. 251-5095" more coloring,strength'.,,than equalfamounts of "commercially,

available hexadec'achloro. copper merits.

ph alo yanine, pi

Eixgmpl e 2 v Example-l was .=repeated, but-:zthc;agitationewamcarried outawith *arhigh speedrwaring -Blendor=,for ,a .fewminutes. at room temperature." Bytthisaprocedure;therheating to;

4. cohol. The results obtained in polyethylene and polyvinyl -chloride were-veryclosely the same as -those ob- 60-? Ct'lwaseliminatedh Aflerfilterlng, .dryingsand grind-r ing; a; produethwas :obtained whiche-was lequal; toltthel product ofi Examplel: in 3113 respects.

Example 3 a 180 parts of copper phthalocyanine-presscake qu lentnto 6Q parts-of :phthalocyanine,on::a:100%.-pigment ,contenc); wasz-slnrriedzin 17.00 parts-oflwatensanditreated.

with 1.5:pants;-,ofiiisooctylalcohoheasiin Exampled; A soft; :fluiiy, bright; b1ue;:pr.oduct s-wassobtained. lwhichzwas excellentrifoncallii applications-,;;butz was especially out-.:

standingwlieniused foncoloringlplasticsa j Example 4 r 180 pm i' of iemdec-achlorm c pper p a o ya presscake equigalfilll; ito. :6Ggpantsgldry basis) of -phthalocyanine; green: presscake preparedby conyentional acid klednonqand-nnilled intoutherapolymermat' 135 C; for 12' minutes Th6,ShB6IS.-'WB1'8 then molded in: a Carver press asr8900 prsii'fonlflminutesg at-2130i=:C.",

' "EXample-f5"' i v :1 ipargt:oi rphthalocyani'neitonerr prepared lineExampl 4; wasrmixedzwithzSikpartsotdioctyl phthalate, and placed on :the T-hrop:mi111 with -.10Qsparts 5.0fi polyvinylschloride; Aftemheatingl ferzfi l-minutesgat 1'65. C-.",.;the;- sheekwas dnamiofiz p Polystyrene; various: acrylic copolymers and a rubber latexrtweretsimila-rly successfnllyemilledwvithi theph thalocyanine pigment. V Tints were observedibyaaddition of titanium dioxide to, reduce the: color. In a typicaligexarnple, utilizing, the procedure described inExam leA, 01 part'of thephthalm y nine, greemtoner and; .03... p rtoffl itani mwdioxide were mill'ed-.;into 100 7 parts oi polyethylene. The -same superior s rength nd Shade characteristics were observed asflcomparedrto the use of commercially available phthalocyanine. pigments similarly. dilutedl-with, the titaniumfiioxide l -7 Examples;

5 Example was-repeated using an equivalentamount'of commercial-mixed amyl alcohols in -place 'ofisooctyljaltained in Examples 4 and 5 in strength, shade and dispersion properties. In a specific comparison of milling with polyethylene as describedinExample 4, the product of Example 6 was, a ,trifie,moreyellowinshade, a trifle weaker andva ,trifle worse, {in vdispersion,

' Example, 7

Example 4 was repeated; but usingonly one,half-as muchiofit-he .isooctyl alcohol. l hQ polyethyl n product was a trifle morer-yellow,--altrifle strongerand the dispersion was very slightly inferior.

Example 8 Example 4was repeated; :but usingz-lOitimes thelamount of isoootylaalqohol; Then-polyethylene productwas a:

trifle morei-vyellomvzhad thews'ame strengthsand; the "dispersionwas slightly inferion- There wouldtbenoradvan-r tagein using more-alcohol.-

z impl y 1 fixamplezxwas a'epeated; but usingone half the-amountof water. The olyethylene productwasequalinshade, a :trifle weak tinestrengthandm ,:trifie;infe1.'iQr ,inedispersion propertiesef Example; 10"

' Example 4 was repeated; but using twice the amount oi'fwater'J. The polyethylene: product was ,a'trifle more yeliowin shadeand'equal instrength and dispersion;

Consequently, there would T be no advantagerin using lar e: m unts of Wa er:

' Example '1 1 Example-4jwas repeated using'an equal-=amount of nheptanol-;in place oftheisooctylalcohol; The polyethylene productwas a-trifle more yellow in shade, equal in strength and a trifle Worse in dispersion.

Example 12 Example4- was-repeated except in-place-ofthe-isooctyl alcohol an equal-amountof-in-nonanoLwas-used. The polyethylene productwas equal in shade,= a-trifie stronger and equa'lin dispersion properties;

tExampl d 3 t desjtabi l il;yv ofhaving wetting agents present during, the

Processed the pr ent 'nr nt 1- Example 14 -Example ,4rwas, repeated, but using isopropyl alcohol ill-place,of,therisooctylalcohol. The polyethylene prodnot: was a trifie more yellow in shade, a trifle stronger and a trifleworse in disjpersion properties. While isopropyl alcoholc'an, therefore; be used, it is to be understood that it'isnot a preferredgalcohol-for use in accordance with the'presentinvention; The preferred alcohols' are the water insoluble alcohols, and most preferably; arethe bctanols andnonanols;

Example. 15

Example 4' was repeated using an equal amountof lauryl alcohol 'inplace of the isooctyl alcohol. The product was equal in shade, a trifle weaker in'strength and g y orse in'dispersion'properties. Lauryl alcohol iis'about the upper limit of 1118 suitablealkanols for-the P e nt invention.

Example 16 20 parts of chlorinated copper phthalocyanine (obtained as in Example 2 of Patent No. 2,195,984) and 5 parts of lauryl alcohol were slowly added to 250 parts of sulfuric acid monohydrate as described in Example 5 of Dahlen Patent No. 2,291,452. After stirring until complete solution, the product was drowned into 2500 parts of water at 90-95 C. and worked up as described in the Dahlen patent.

As compared with the polyethylene product obtained in Example 4, a similar polyethylene product using the pigment of Example 16 in the same amount as the pigment used in Example 4 had only about of the color value, was very blue and dull and had very poor dispersion.

Example 17 Example 16 was repeated except that isooctyl alcohol was used in place of the lauryl alcohol. This product was an improvement over that prepared in Example 16, but when milled with polyethylene, gave a product which only was about 30% as strong, was bluer, a trifle duller and showed very poor dispersion as compared to the polyethylene product in Example 4.

A comparison of Examples 16 and 17 with Example 4 illustrates the fact that it is critical to add the alkanol to the presscake after the acid pasting rather than merely adding the alcohol during the acid pasting itself.

Example 18 30 parts of copper phthalocyanine were slowly dissolved in 400 parts of 96% sulfuric acid and stirred until complete solution occurred at 50-55 C. This melt was drowned into 3000 parts of water containing 1000 parts of ice. The precipitate was filtered and washed neutral with water. The filter cake was reslurried in 300 parts of water. 0.84 part of isooctyl alcohol was added, and the whole heated to 60 C. and held there for two hours with stirring. After screening through a 200 mesh screen, the product was filtered, dried and micro-pulverized. This product imparted to polyethylene a strong blue shade having excellent dispersion when used in place of the phthalocyanine green pigment in the polyethylene milling procedure described in Example 4. A similar strong, blue shade was imparted to polyvinyl chloride using the milling procedure described in Example 5.

Example 19 30 parts of copper phthalocyanine and 3 parts of lauryl alcohol were added to 300 parts 98% sulfuric acid containing 3 parts of pyridine at 0-5 C. After stirring to complete solution, the product was drowned into 3000 parts of water at 90-95 C. and worked up according to Examples 1-3 of Dahlen Patent 2,291,452. This product, when tested in polyethylene and polyvinyl chloride blends in the identical manner as in Example 18, had only about 70% of the strength, was redder and duller and had poorer dispersion properties than the product prepared in that example. Froma comparison of Examples 18 and 19, it can be seen that with phthalocyanine blue pigments, it is also critical that the alkanol be added after the acid pasting step and not merely during the acid pasting.

Example 20 Example was repeated but, in addition to the lauryl alcohol, there was also added 1.5 parts of pyridine. The polyethylene product was considerably weaker in shade,

weaker in strength and worse in dispersion than the corresponding product of Example 15.

We claim:

1. A process consisting essentially of slurrying a phthalocyanine presscake with water containing a minor amount of a member of the group consisting of cyclohexanol and an unsubstituted alkanol having at least three carbon atoms and only one hydroxyl group, said phthalocyanine being selected from the group consisting of copper phthalocyanine, chloro copper phthalocyanine, aluminum phthalocyanine and chloro aluminum phthalocyanine.

2. A process according to claim 1 wherein the phthalocyanine is copper phthalocyanine.

3. A process according to claim 1 wherein the phthalocyanine is chloro copper phthalocyanine.

4. A process of treating a phthalocyanine presscake prepared by acid pasting, said process consisting essentially of slurrying the presscake with a mixture consisting essentially of water containing a minor amount of a water insoluble monohydric alkanol having 5 to 12 carbon atoms, said phthalocyanine being selected from the group consisting of copper phthalocyanine, chloro copper phthalocyanine, aluminum phthalocyanine and chloro aluminurn phthalocyanine.

5. A process according to claim 4 wherein the phthalocyanine is copper phthalocyanine.

6. A process according to claim 4 wherein the phthalocyanine is chloro copper phthalocyanine.

7. A process according to claim 6 wherein the phthalocyanine is hexadecachloro copper phthalocyanine.

8. A process according to claim 4 wherein there is used from about 0.01 to about 0.25 part of the alkanol per part of the phthalocyanine.

9. A process according to claim 8, wherein there is added about 4 to 20 parts of water per part of phthalocyanine.

10. A process according to claim 4 wherein the alkanol is isooctyl alcohol.

11. A process according to claim 4 wherein the alkanol is nonanol.

12. A process according to claim 4 wherein the alkanol is heptanol.

13. A process according to claim 4 wherein the alkanol is lauryl alcohol.

14. A process according to claim 4 wherein the alkanol is amyl alcohol.

15. A process according to claim 1 wherein there is used from about 0.01 to about 0.25 part of the alcohol per part of the phthalocyanine.

16. A process according to claim 1 wherein there is added about 4 to 20 parts of water per part of phthalocyanine.

17. A phthalocyanine treated according to the process of claim 1. 1

References Cited in the file of this patent UNITED STATES PATENTS 2,296,382 Fischer et al Sept. 22, 1942 2,316,535 Bahner et al Apr. 13, 1943 2,327,405 Davidson et al Aug. 24, 1943 2,367,519 ONeal Jan. 16, 1945 2,456,274 Gutzwiller Dec. 14, 1948 2,469,663 Moser May 10, 1949 2,489,226 Morris et al. Nov. 22, 1949 2,548,376 Jones Apr. 10, 1951 2,859,219 Randall et al Nov. 4, 1958 

1. A PROCESS CONSISTING ESSENTIALLY OF SLURRYING A PHTHALOCYANINE PRESSCAKE WITH WATER CONTAINING A MINOR AMOUNT OF A MEMBER OF THE GROUP CONSISTING OF CYCLOHEXANOL AND AN UNSUBSTITUTED ALKANOL HAVING AT LEAST THREE CARBON ATOMS AND ONLY ONE HYDROXYL GROUP, SAID PHTHALOCYANINE BEING SELECTED FROM THE GROUP CONSISTING OF COPPER PHTHALOCYANINE, CHLORO COPPER PHTHALOCYANINE, ALUMINUM PHTHALOCYANINE AND CHLORO ALUMINUM PHTHALOCYANINE. 